The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

Aust set to help detained artist in China

Australia has let China know it has strong interest in the case of a Chinese-Australian artist detained in Beijing ahead of the Tiananmen Square anniversary.

Guo Jian, a former Tiananmen Square protester, was taken on Sunday from his home in Songzhuang, an art colony on the eastern fringe of Beijing, the Sydney Morning Herald reports.

The paper says Mr Guo's friends believe he was taken because of a recent interview with the Financial Times in which he said he had created an artwork to privately commemorate the anniversary, covering a large diorama of Tiananmen Square with 160 kilograms of minced meat.

The 52-year-old Chinese-born Australian managed to send two short text messages, saying he had been taken by police, the report said.

The Department of Foreign Affairs is poised to extend "all possible" consular assistance to Mr Guo.

"The Australian embassy in Beijing has contacted Chinese authorities to seek further information on the reported detention of Mr Guo Jian and to underline our strong interest in the matter," a DFAT spokesman said in a statement on Monday.

"The Australian government stands ready to extend all possible consular assistance to Mr Guo."